/**
 *
 * @param {Element} doc
 */
function fullScreenChange(doc) {
  if ($(doc).hasClass("fullscreen-btn")) {
    $(doc).removeClass("fullscreen-btn");
    $(doc).text("全屏");
    $(doc).parent().children("iframe").removeClass("fullscreen-iframe");
  } else {
    $(doc).addClass("fullscreen-btn");
    $(doc).text("退出全屏");
    $(doc).parent().children("iframe").addClass("fullscreen-iframe");
  }
}
